Rheological and adherence properties of sickle cells. Potential contribution to hematologic manifestations of the disease.

Hematologic manifestations of sickle cell disease are varied and complex, and there is also a great variation in these manifestations among different individuals with the disease. While substantial efforts have been invested in defining the cellular basis for these clinical manifestations--including the evaluation of the potential contributions of intracellular polymer content, kinetics of hemoglobin polymerization, rheological abnormalities, oxidant membrane damage, and adherence of sickle cells to vascular endothelial cells--we are still far from understanding the relative contributions of each of these factors to varied manifestations of the disease. While the data discussed in this paper raise interesting issues regarding the potential contribution of rheological and adherence properties of sickle cells to altered flow dynamics in the microvasculature, they fall short of defining the direct contributions of these factors to various clinical manifestations. Further detailed characterization of various cellular abnormalities of sickle cells and how each of these factors acting alone or in combination with other cellular and extracellular factors such as microvasculature changes contribute to different clinical manifestations will be needed to further our understanding of the pathophysiology of this complex disorder.